Palynological investigations in the Orce Archaeological Zone, Early Pleistocene of Southern Spain

Palynological investigations in the Orce Archaeological Zone (OAZ) (Guadix-Baza Basin, Granada, Spain), Venta Micena 1 (VM1), Barranco Leon (BL) and Fuente Nueva 3 (FN3) are presented. This archaeological region is con-nected with the first Homo populations in Western Eurasia during the Early Pleistocene. The VM1 pollen record is characterized by Ephedra, and to a lesser extent, Pinus, Juniperus and evergreen Quercus, occassionally accompa-nied by Olea, Genisteae, Erica, deciduous Quercus, Alnus, Castanea, Fraxinus, Salix and Phillyrea. BL is dominated by Juniperus, Olea, Pinus, Poaceae, and evergreen Quercus. FN3 is characterized by an open Mediterranean woodland dominated by evergreen Quercus, Pinus, Juniperus and Olea, accompanied by deciduous Quercus, Castanea, Populus, Salix, Ulmus, Fraxinus, Pistacia, Phillyrea, Genisteae, Erica, Cistus, and Ephedra fragilis. Relic Tertiary taxa in OAZ include Carya, Pterocarya, Eucommia, Zelkova, and Juglans. The Early Pleistocene OAZ vegetation is a mosaic of different landscapes embracing mesophytes, thermophytes, xerophytes, xerothermophytes, and Mediterra-nean elements. These finds are compared with former pollen analyses in the region and beyond within the Ibe-rian Peninsula. (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).Peer reviewe

To den or not to den. Contributions to the taphonomic history of the Early Pleistocene site of Venta Micena 4 (Orce, Guadix-Baza Basin)

Venta Micena (Orce, Guadix-Baza Basin, Spain) is an Early Pleistocene locality renowned for the richness and quality of its palaeontological record. VM is spread over an area of 2.5 km2, where several exposed fossil outcrops are visible amidst its gorges and ravines. The best known of these sites, VM3, has been interpreted as a hyaena den. In addition, a new site, named VM4, has recently been the focus of fieldwork and taphonomic studies. The publication by Luzón et al. (2021) pointed out that VM4 presents a more complex history than VM3. First, two different sub-levels were identified: VM4-I and VM4-II. Secondly, the preliminary taphonomic analysis showed conspicuous differences with regard to VM3. Nevertheless, such interpretation has been challenged by Palmqvist et al. (2022) who proposed that VM3 and VM4 are both the result of a single depositional process, entailing the selective transport of skeletal parts by the giant extinct hyaena Pachycrocuta brevirostris back to its den. Using well-preserved faunal elements whose depositional context and provenance are reliable, in this paper we show that: 1) there are two clearly defined sub-levels in VM4 with some shared taphonomic characteristics as well as some notable differences; 2) VM3 and VM4 exhibit enough divergence to support differences in site formation processes; 3) The interpretation of both VM4-I and VM4-II is more consistent with their characterisation as open-air sites in which multiple agents and depositional processes contributed to its formation, rather than with hyaena dens. Nevertheless, excavations are still in progress at VM4 and therefore any results and interpretations ought to be considered as provisional

Merging paleobiology with conservation biology to guide the future of terrestrial ecosystems

Conservation of species and ecosystems is increasingly difficult because anthropogenic impacts are pervasive and accelerating. Under this rapid global change, maximizing conservation success requires a paradigm shift from maintaining ecosystems in idealized past states toward facilitating their adaptive and functional capacities, even as species ebb and flow individually. Developing effective strategies under this new paradigm will require deeper understanding of the long-term dynamics that govern ecosystem persistence and reconciliation of conflicts among approaches to conserving historical versus novel ecosystems. Integrating emerging information from conservation biology, paleobiology, and the Earth sciences is an important step forward on the path to success. Maintaining nature in all its aspects will also entail immediately addressing the overarching threats of growing human population, overconsumption, pollution, and climate change.Peer reviewe

A multi-proxy approach to the palaecological reconstruction of the Orce Basin Archaeological Zone (Granada, Spain)

Comunicación oral presentada en XXI INQUA Congress. July 14th – 20th 2023, Rome (Italy)The Orce Basin Archaeological Zone (OZAB, Granada, Spain) extends over a surface area of some > 8.5 km2 and constitutes one of the richest Pleistocene vertebrate fossil records in western Europe including one of the oldest hominin presence in this part of Eurasia. Exceptionally rich collections of stone tools have been excavated from both of the Orce Oldowan sites: Barranco León (BL) (1.4 Ma) and Fuente Nueva 3 (FN3) (1.2 Ma), while BL has yielded a hominin deciduous lower molar. We present a multi-proxy approach to determine the palaeoeocological context of these first hominin settlements in Western Europe. By combining results from macrovertebrates, microvertebrates, as well as from pollen and stable isotopes from macrovertebrate tooth enamel, we determine whether the palaeo landscapes were dominated by savanna or open woodland. The results reveal the regional specificities of the OAZB, and also allow us to infer local features within the Orce sites. Overall, our data reveal the dominance of a typically Mediterranean climate and landscape since 1.8 Ma ago. The climatic conditions were generally more humid than at present, with warmer temperatures during the coldest months, indicating a higher net primary productivity (NPP). We find that precipitation and NPP appear to have been limiting factors for hominin presence in the OAZB. Thus, at the older palaeontological site of Venta Micena (1.6 Ma), climatic conditions appear to have been less compatible with hominin presence than during the BL and FN3 sequences, when early hominins inhabiting the OAZB were able to cope with changing climatic and environmental settings. Lastly, the comparison of the isotopic results of the Orce sites with those of the contemporaneous Shungura Formation (Ethiopia) reveals that the habitat in the westernmost part of Eurasia was distinctly unlike a typical African savanna

Approaching a state shift in Earth’s biosphere

Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence. The plausibility of a planetary-scale ‘tipping point’ highlights the need to improve biological forecasting by detecting early warning signs of critical transitions on global as well as local scales, and by detecting feedbacks that promote such transitions. It is also necessary to address root causes of how humans are forcing biological changes.Peer reviewe

Approaching a state shift in Earth's biosphere

Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence. The plausibility of a planetary-scale ‘tipping point’ highlights the need to improve biological forecasting by detecting early warning signs of critical transitions on global as well as local scales, and by detecting feedbacks that promote such transitions. It is also necessary to address root causes of how humans are forcing biological changes

Toward a holistic understanding of pastoralism

Summary Pastoralism is globally significant in social, environmental, and economic terms. However, it experiences crises rooted in misconceptions and poor interdisciplinary understanding, while being largely overlooked in international sustainability forums and agendas. Here, we propose a transdisciplinary research approach to understand pastoralist transitions using (1) social, economic, and environmental dimensions, (2) diverse geographic contexts and scales to capture emerging properties, allowing for cross-system comparisons, and (3) timescales from the distant past to the present. We provide specific guidelines to develop indicators for this approach, within a social-ecological resilience analytical framework to understand change. Distinct systems undergo similar transitions over time, crossing critical thresholds and then either collapsing or recovering. Such an integrated view of multidimensional interactions improves understanding of possible tipping points, thereby supporting better-informed decision making. The need for a paradigm shift in pastoralism science and policy is pressing. This research approach, including participatory methods, can provide the solutions urgently needed